te Pas Arjan B, Davis Peter G, Kamlin C Omar F, Dawson Jennifer, O'Donnell Colm P F, Morley Colin J
Division of Newborn Services, Royal Women's Hospital, Carlton, Victoria 3053, Australia.
Pediatr Res. 2008 Sep;64(3):281-5. doi: 10.1203/PDR.0b013e31817d9c35.
There are no data describing how very preterm infants breathe spontaneously immediately after birth. We studied a convenience sample of spontaneously breathing infants <or=32 wk' gestation treated with facemask continuous positive airway pressure at birth. Airway pressure and flow were measured and each breath analyzed. Twelve infants had 792 breaths suitable for analysis. Results are given as mean (SD). Gestational age and birth weight were 29 (1.9) wk and 1220 (412) g. Recordings were started 159 (77) s after birth. The inspiratory pattern and duration was similar in all breaths at 0.36 (0.11) s. There were five expiratory patterns; most infants had more than one. In 79% of breaths expiratory duration (1.6 (1.1) s) was slowed or held by interruption or braking of expiratory flow. It was braked in 47% to a complete expiratory hold, in 22% by grunting or crying, and in 10% by slow or interrupted expiration. In 21% of the breaths, expiration was not interrupted and lasted 0.53 (0.13) s. Half of these breaths represented a panting pattern (rate >60 /min). Immediately after birth, most very preterm infants, treated with continuous positive airway pressure, frequently prolong their expiration by braking the expiratory flow.
尚无数据描述极早产儿出生后立即的自主呼吸情况。我们研究了一个便利样本，即出生时接受面罩持续气道正压通气治疗的孕龄≤32周的自主呼吸婴儿。测量气道压力和气流，并分析每一次呼吸。12名婴儿有792次适合分析的呼吸。结果以均值（标准差）表示。孕龄和出生体重分别为29（1.9）周和1220（412）克。记录在出生后159（77）秒开始。所有呼吸的吸气模式和持续时间相似，为0.36（0.11）秒。有五种呼气模式；大多数婴儿有不止一种。在79%的呼吸中，呼气持续时间（1.6（1.1）秒）因呼气气流的中断或制动而减慢或暂停。其中47%的呼吸制动至完全呼气暂停，22%因呻吟或哭闹，10%因缓慢或间断呼气。在21%的呼吸中，呼气未被中断，持续时间为0.53（0.13）秒。这些呼吸中有一半表现为喘息模式（频率>60次/分钟）。出生后立即，大多数接受持续气道正压通气治疗的极早产儿经常通过制动呼气气流来延长呼气时间。
